Create documentation for new people joining an LF project and what to expect in CI.

This doc should introduce people to the CI setup (Gerrit / Jenkins / Jira). From there we should list things folks should be aware of:

• Types of jobs that they should be aware of (verify, merge, csit, etc...)
• Gerrit comment triggers (recheck, remerge, run-sonar, run-clm, jjb-deploy)